Holy sh*t! Is this effect typically taught / introduced in a GR course? Why did I not know this!? EDIT> Is there any way to derive this outside of GR? EDIT2>

Holy sh*t! Is this effect typically taught / introduced in a GR course? Why did I not know this!? EDIT> Is there any way to derive this outside of GR? EDIT2> I notice that you were careful to say "heavier", not more "massive". Does this point to the effect being part of the gravitational interaction specifically?